Steam-boiler



(No Model.) 2 Sheets-Sheet 1.

T. DRUMMOND.

STEAM BOILER.

No. 322,701. Patented July 21,1885.

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' T. DRUMMOND.

STEAM BOILER. NO. 322,701. Patented July 2 1, 1885.

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UNITED. STATES 'ATENT OFFICE.

THOMAS DRUMMOND, OF NORWICH, CONNECTICUT.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 322,701, dated July 21,1885.

Application filed April 2, 1885. (No model.)

To all whom it may concern:

Be it known that I, THOMAS DRUMMOND, a citizen of the United States,residing at Norwich, in the county of New London and State ofConnecticut, have invented certain new and useful Improvements inSteam-Boilers,which improvements are fully set forth and described inthe following specification, refer ence being had to the accompanyingdrawlugs.

My improvements relate particularly to vertical cylindricalsteam-boilers, my immediate object being to produce in compact form andat a reasonable cost a boiler having, first, an increased amount ofheating-surface; second, increased facilities for cleaning the tubes,and, third, perfect draft and combustion. In the annexed drawings,Figure 1 is a vertical sectional view through the center of mynewly-improved steam-boiler, and Fig. 2 is a cross-section on linear wof Fig. 1. Fig. 3 is a side view of said boiler complete, and Fig. 4. afront View of the same, one of the doors being opened to expose thetubes.

The letter A represents the outer shell or case, having the usual dome,B. Within the outer case, A, is an inner shell, C, concentric with saidouter case on the backside of the boiler and extending upward to orslightly above the upper line of draft-tubes, forming a thin water-spacearound the firebox and in the rear of the lower main flue,a.The-crownsheet of the fire-box is concaved and is rounded at its rearside, as shown at b in Fig. l, to provide a free and unobstructed exitfrom said fire-box into the lower main flue, a.

Extending upward from the rounded portion b is a partition, 0, (dividingthe water and fire spaces,) which meets and is secured to the upper wallof the flue a, said flue being shaped in crosssection as a segment of acircle. (See Fig. 1.) Near the front side of the boiler and opposite tothe partition 0 is a corresponding partition, d, whose lower end restson a baseplate, f, whose outer circular edge is secured to the shell A,thus forming the base of the upper main flue, 6, leading to the chimney.The partitions c d are perforated to receive and support a series ofhorizontal tubes h, which, passing through the waterspace, formconnecting draft-passages between the lower and upper lines, a e.

The crown-sheet or head of the boiler C has a circular extension, E,which surrounds the draft-flue 6, thus furnishing a suitable steam-dome.

It will thus be seen that the water-space is disposed immediately overand around the fire-box; that the flue a is entirely surrounded by thewater-space; that the horizontal tubes h conduct the heat through thecenter of said water-space, and that the upper flue, 6, then carriessaid heat upward through the steamchamber and dome, utilizing said heatto the fullest extent up to the instant it passes into the chimney. Bythus cutting up the waterspaoe I am able to generate a given pressure ofsteam much quicker than if the water was in a single sheet or body, andalso to hold said pressure with greater economy of fuel thanin any ofthe boilers of this class with which I am familiar.

For convenience in cleaning out the drafttubes h, I have arranged one ormore doors, is k, which confront the partition (2, and when openedexpose the tubes, which may then be readily cleaned by brushing,scraping, or by any of the methods in common use.

As the various necessary connections, such as feed-water pipe,pressure-gages, safetyvalve, &c., are made in my improved boilerprecisely the same as in boilers now in common use, I have thought itunnecessary to show and describe them here.

The compact form into which my complete boiler is brought renders itespecially valuabio for use in small steamboats and other similar placeswhere economy of floor-space is to be considered.

Having thus described my invention, I claim The combination, in asteam-boiler, of the fire-box having a curved crown-sheet, the verticalflue at the rear, the smoke box and its escape-flues at the front, andthe intermediate horizontal flues connecting the vertical fines andsmoke-box, substantially as and for the purposes specified.

THOMAS DRUMMON D.

Witnesses FRANK H. ALLEN, TYLER J. HOWARD,

